Pumping well apparatus



4 Sheets-Sheet 1 May 2, 1961 o. N. RODGERS PUMPING WELL APPARATUS FiledJan. 24, 1958 Of/J N90 Foo gems INVENTOR.

BYfi V ATTO/P/VE) y 2, 1961 o. N. RODGERS 2,982,355

' PUMPING WELL APPARATUS Filed Jan. 24, 1958 4 Sheets-Sheet 2 INVENTOR.

0. N. RODGERS PUMPING WELL APPARATUS I May 2, 1961 Filed Jan. 24, 1958 4SheetsSheet Z5 Of/J A/ea Poo 76A;

INVENTOR.

ATTORNEY May 2, 1961 o. N. RODGERS PUMPING WELL APPARATUS 4 Sheets-Sheet4 Filed Jan. 24, 1958 Of/J A/eo Poo yen:

INVENTOR.

ATTORNEY United States, Patent PUMPING WELL APPARATUS Filed Jan. 24,1958, Ser. No. 711,028

Claims. c1. 166-68) This invention pertains to well pumping assemblies.

The objects of the invention are to prevent leakage of the tubing jointsand wear of the pump rods on the tubing, without risking locking thetubing in the casing.

Other objects and advantages of the invention will appear from thefollowing description of a preferred embodiment thereof, reference beingmade to the accompanying drawings wherein:

Figure 1 is a schematic section of a well incorporating a pumpingassembly embodying the invention, the pump rod being on the downstroke;

Figure 2 is a view similar to Figure 1 except that the pump rod is onits upstroke;

Figure 3 is a vertical section through the tubing anchor used in theassembly;

Figure 4 is a horizontal section on line 4-4 of Figure 3;

Figure 5 is a horizontal section on line 5-5 of Figure 3;

Figures 68 are views similar to Figures 3-5 showing a modification; and7 Figures 9' and 10 are views similar to Figure 1- showing installationof the modification.

Referring now to Figures 1 and 2, there is shown a well casing 10. Thecasing is perforated at 11 adjacent the producing formation to admitoil. The oil is pumped up and out of the well through a string of tubing12. The tubing is hung concentrically inside the casing by means of asuitable slip suspension means 12A.

A tension in the tubing throughout its length in addition to thatproduced by its own weight is achieved by anchoring the tubing at itslower end and then pulling up on the tubing and holding it with thesuspension means 12A. Thus, even at the lower end of the tubing wherethe tension due to its own weight approaches zero there will be at leasta minimum tension of the desired amount.

The tubing anchor includes an upwardly pointing slip expander cone 13 onthe lower end of the tubling. Around the cone are a plurality of slips14 held in a cage 15-. The cage 15 does not allowthe slips to movevertically relative thereto but permits them to move radially in or outas the cone is moved down or up relative to the cage. When the tubing isbeing lowered intothe casing, the slip cage is held against axialmovement relative to the expander cone by a slot 42 and pin 41connection, the relative position of cage and cone being such that theslips are retracted. When it is desired to set the anchor the frictiondrag blocks 16 hold the cage against turning in the casing while thetubing is rotated to unlock the slot and pin connection. Upward movementof the tubing then causes the expander cone to move up relative to theslip cage to force the slips radially out into anchoring engagement withthe casing.

The slip cage carries a pump barrel 20 at the lower end of which is aball check standing valve 21. Beneath the standing valve is tailpipe 22.Instide the pump barrel is a piston 23w having a packing 24- therearoundsealing to the pump barrel. A passage 25 through the piston iscontrolled at its upper end by a ball check traveling valve 2-6connected to the upper end of the piston. The traveling valve isconnected to the lower end of a string of sucker rods 27. The suckerrods are raised and lowered periodically by a suitable means, e.g. ahydraulic pumping unit 28. The traveling valve is open to the spaceinside of the tubing so that when the valve is open the tubing is incommunication with the pump barrel through passage 25- as shown inFigure 1.

When, as shown in Figure 1, the piston and traveling valve are movingdown the traveling valve is open and the standing valve is closed andthe weight of the oil or other well fluid is on the well casing, beingtransmitted thereto from the standing valve through the pump barrel,slip cage, and slips. When, as shown in Figure 2, the piston andtraveling valve are moving up, being pulled by the sucker rods, thetraveling valve is closed and the standing valve is open. In this casethe well fluid is entering the pump barrel through the standing valveand the weight of the well fluid in the tubing is on the sucker rods,being transmitted thereto from the piston and traveling valve.

It isclear therefore, that the tubing tension does not vary during thepumping cycle. On the upstroke the weight of well fluid is on the suckerrods and the tubing tension is taken by the slips and casing. On thedownstroke the weight of the well fluid is on the slips thus helping thecasing hold the tubing in tension. The initial minimum tension in thetubing is greater than the weight of the well fluid so that puttingtheweight of the well fluid on the slips does not increase the tubingtension, merely takes part of the force off the casing. Since the tubingtension does not vary, there is no working of the tubing joints duringthe pump cycle and hence no leaks are apt to develop.

Since the tubing is in tension it will be straight and consequentlythere will be little or no rubbing of the sucker rods on the tubing. Itis to be noted that the sucker rods are also in tension since they hangfreely under their own'weight or the added weight of well fluid on theupstroke. Therefore the sucker rod string will also be straight if thetubing is vertical. However if the tubing is not vertical there will bea slight catenary in the sucker rod string which may make it desirableto use sucker rod centralizersat a few points along the length of thestring. The absence of kinks, buckling, and corkscrewing of the tubingmakes it easy to use such centralizers if the need arises. The life ofthe sucker rods and tubing are thus prolonged due to the absence of wearcaused by sucker rods rubbing on the tubing.

When it is desired to pull the tubing, for example to repair the pump,the tubing is lowered to drop the expander cone. Means such as dovetailson the slips engaging correlative slots in the expander cone cause theslips to be'retracted as the expander cone'moves down relative thereto,the slip cage remaining stationary due to the friction of the dragblocks against the casing. The locking means comprising the slot and pinconnection are then re-engaged by rotation of the tubing, and the tubingstring and parts dependent therefrom can all be removed.

Should the drag blocks fail to hold-the slip cage stationary duringdownward motion of the tubing, due to excess weight of pump barrel,standing valve, and tailpipe, or due to binding or jamming of the slipson the expander cone, whereby the slips are not fully retracted, thetubing can be lowered until the tailpipe touches bottom and positivelyprevents further downward movement of the slip cage. Suflicient weightof tubing can then be placed on the expander cone to force it downrelative;

to the slips so that the slips are fully retracted and the Patented May2, 1961 looking means can be engaged and the string withdrawn 7 from thewell.

Referring now to Figures 3-5, there are shown the details of the tubinganchor which comprises a hollow mandrel 30 adapted to be connected tothe tubing 12 and having tubular expander cone 13 screwed thereto. Thehollow mandrel 30 thus provides tubular means for connecting the tubularexpander cone 13 to the tubing 12; the cone 13 provides a tubulartapered slip expander means; and the mandrel 30 and cone 13 form atubular body for the anchor on which the slips 14 and cage 15 aremounted. The slips 14 are disposed in openings 31 in the slip cage 15.Dovetails 32 on the slips engage slidably in correlative openings 33 inthe expander cone. Friction drag blocks 16 are disposed in recesses 34in the slip cage, being urged outwardly by springs 35 and limited intheir outward motion by the heads of screws 36. The slip cage, dragblocks, and springs provide slip control means tending to hold the slipsagainst axial movement relative to the casing while permitting radial inand out movement of the slips between a retracted position and anextended position in anchoring engagement with the casing.

There is a parting section of reduced wall thickness formed in themandrel 30 at 37. In case the slips 14 cannot readily be freed from theexpander cone 13, a suflicient upward pull on the tubing string willcause the mandrel 30 to break at parting section 37. The tubing willthen contract quickly, and slip raising means in the form of flange 38,formed on the mandrel above the parting section, then cooperates withthe slip control means by moving upwardly within annulus 39 between themandrel and slip cage until it strikes inwardly extending radial flange40 on the slip cage, the resulting impact on the slip cage jarring theslips free from the expander cone and raising the slips relative to thecone. If the first impact does not free the slips, the telescopicjointformed by the upper part of the mandrel and the slip cage can beoperated as a jar by alternately lowering and raising the tubing string,the flange 38 alternately striking the lower part of the mandrel and theflange 40 to drive the cone and slips apart.

At the lower end of cage 15 is screwed pipe 15a adapted to slide on thecylindrical bottom extension 13a of the expander cone 13. Pipe 15a islimited in its upward movement relative to extension 13a by a downwardlyfacing shoulder 13b formed at the juncture of the upper part of cone 13with its bottom extension 13a. It is at this shoulder that force istransmitted from the expander cone to the slip cage to force the latterdown against the resistance of drag blocks 16 as the tubing string islowered.

Pipe 15a carries a pin 41 which cooperates with inverted L-shaped slot42 in extension 13a to form a means for releasably locking the cage tothe expander cone against relative axial movement. rings 43, 44 sealbetween extension 13a and pipe 15a above and below the locking means tokeep it free of dirt. By this means there is provided a fluid tighttelescopic joint connecting the pump barrel to the tubing. In theposition shown in Figure 3 the locking means is engaged, the pin 41being in the upper part of the inverted L-shaped slot 42 and displacedazimuthally from the vertical part of the slot. The tubing can thereforebe raised, if need be, without setting the slips. By turning the tubingclockwise a quarter turn the vertical part of the slot will come underpin 41 and the locking means will be released. The anchor can then beset by pulling up on the tubing, thus driving the slips radially outwardwith the cone until the slips bite into the casing. By the reverseprocedure the slips are unset and the locking means re-engaged so thatthe tubing can be raised for removal or resetting at a different level.It is to be noted that the vertical extent of slot 42 is sufiicient toallow the slips to set. The vertical extent of annulus 39 is greaterthan the travel needed 4 to set the slips so that in the set positionthere is still space between flanges 38 and 40, thus providing a freedomof motion when the parting section 37 is broken and the slips are to bejarred free.

The teeth or wickers 50 on the slips 14 are neutrall directed so as tohold against both upward and down-- ward forces, although normally theywill be called upon to hold only against upward pulls, that is, tofunction as holddown slips. However if the tubing tension should beinitially set at less than the weight of well fluid being pumped, or ifthe tubing tension should slack off to such a value, then when theweight of well fluid is transferred to the slips they will transfer theload largely to the casing with very little added tension being placed011 the tubing by the expander cone. In this latter case the slips serveas hold-up slips during at least half of each pump cycle.

In some wells the pump is desirably located at a level considerablyabove the producing formation, in some cases many hundreds of feet. Insuch cases there is a considerable length and weight of tailpipeextending down from the anchor. If the weight is greater than can besupported with certainty by friction drag blocks of reasonable size, themodified construction shown in Figures 6-10 may be used. Thisconstruction is in many respects identical with that of Figures 1-5 sothat corresponding parts have been given the same number increased by100.

Referring to Figure 6, the principal difference in the modified tubinganchor lies in the fact that the tailpipe 122 is hung from the downwardextension 113a of the expander cone 113 rather than from pipe 115ascrewed to the lower end of slip cage 115. This takes the tailpipeweight otf of the drag blocks 116 so that they can more certainly holdthe slips axially stationary in the well casing when it is desired toset or unset the anchor.

It will be noted that in Figure 6 the anchor is shown in set position,the slips being moved radially outward from the position shown in Figure3, so as to engage a well casing. When it is desired to release theanchor, the tubing is lowered and the drag blocks hold the slips axiallystationary in the casing so that they are radially retracted as thetubing 130 and expander cone 113 move downwardly. There is no tailpipeweight tending to pull the slips down along with the cone. It istherefore possible to free the slips, and when pin 141 reaches the topof L slot 142, the tubing is rotated to re-engage this locking meanspreventing the slips from moving downwardly relative to cone 113 whenthe tubing is pulled up. The reverse procedure is followed in initiallysetting the anchor.

With the modified anchor of Figure 6, as with that shown in Figure 3, itis still possible that the slips may become so corroded after a longperiod in the well as to bind themselves to the expander cone so firmlythat the resistance of the drag blocks cannot free them when an attemptis made to unset the anchor. Also, the springs of the drag blocks maylose their force or corrode to the point where they break, so that thedrag blocks no longer engage the casing firmly enough to hold the slipsaxially stationary during the unsetting procedure. With the Figure 6construction it is not possible to free the anchor by lowering thetailpipe to bottom, even if enough spare tubing length is available, forthe slips are not connected to the tailpipe as in Figure 5. However theprovision of the parting section 137 in the mandrel 130 and thetelescopic joint between mandrel 130 and cage 115 provides a means offreeing the anchor and renders this modified construction practical.

The parting section construction shown in Figure 6 is slightly modifiedfrom that of Figure 3 in that mandrel portion below the groove 137 is oflarger diameter, being equal to that of portion 161 above, so that theinterior 162 of the mandrel opposite portions 160, 161 and groove 137can be machined and finished to a closer tolerance than the interior 163of the rest of the mandrel whereby the thickness of the mandrel wall atthe parting section is more accurately controlled.

The mandrel portion 160 below the groove also pro vides a shoulder 164for sealing engagement with the upper end 165 of cone 113 when thethreads between the mandrel and cone are fully made up.

Except as noted above, the tubing anchor construction of Figure 6 isthesame as that of Figure 3, and with the correlated numbering furtherdescription canbe obtained by referring back to the description of theFigure 3 construction. The same is true of Figures 7 and 8 when comparedwith Figures 4 and 5.

Referring now to Figure 9, there is shown a well including a pumpingassembly and incorporating the modified tubing anchor of Figures 6-8.The part numbering corresponds to that of Figure 1, except for theaddition of 100 to each number, so that the description of Figure 1 canbe oorrelatedtherewith. Outside of the modified anchor construction, theonly differences from the Figure 1 construction lies in the pump barrel120, which instead of being of the same diameter as the tubing andtailpipe is of a smaller diameter so as to fit within seating nipple170. After the tubing and anchor have been run into the well and theanchor set and the desired tension taken on the tubing, as with theFigure 1 construction, the whole pump including the standing valve 121,piston 123, packing 124, traveling valve 126, and barrel 120 are loweredthrough the tubing on thesucker rods 127 until the barrel rests on seat171 in the seating nipple, whereupon conventional means, not shown,automatically latches the barrel in place.

The pump seating nipple is connected in the tubing string by means ofcouplings 180, 187. The preferred location is just above the tubinganchor as shown in Figure 9; however the seating nipple and pump can belocated above or below the preferred position, if desired, includinglocations below the anchor in the tailpipeas in Figure 1.

It is preferred to place the seating nipple above the parting section137 so that if the sucker rods break, the impact of their weight as theyfall and the pump piston is driven against the standing valve will notbe taken by the parting section, which might otherwise part under suchloading. Breakage of the parting section would necessitate pulling thetubing as well as fishing out the sucker rods. It will be noted fromFigure 9 that the parting section 137 is of less wall thickness than thetubing 112, which is inherent in its function of parting undersufficient tubing tension.

Another reason for placing the pump seating nipple above the anchor isthat the pipe below the anchor is not tensioned by the anchor.

It is preferred to place the seating nipple immediately above the tubinganchor so as to gain the stabilizing effect of the anchor which holdsthe tubing string to the casing. Also, any section of pipe below thepump need not be placed in tension.

Although in Figure 9, and also in Figure 10, as will be described, apump barrel is shown that is run into the well intoa seating nippleafter the tubing-has been run in, it will be understood that pumpbarrels forming part of the flow string as in Figures 1 and 2 can alsobe used with the anchor of Figures 6-8.

Figure 10 illustrates the installation of the Figure 6 anchor in a wellsimilar to Figure 9 except that the tubing suspension at the well headis by means of a threaded flange 190 instead of slips 112A as in Figure9. Such a suspension does not allow for taking an upward pull on thetubing to place it in tension. With this arrangement the tubing can betension ed by filling the tubing with fluid, e.g. by operating the pump,which will cause the anchor to creep down the inside of the well casing,and then placing the weight of the sucker rods on the tubing through thepump piston, standing valve, pump barrel and seating nipple. Thisprocedure will place a greater weight on the anchor than it will everencounter during normal pumping operations so that there will be noslight movement of the anchor as the weight of well fluid is alternatelyimposed on the tubing and the sucker rods during pump operation.

It is to be noted that with the anchor of Figures 6-8 installed as shownin Figures 9 and 10, if the tubing tension is greater than the weight ofwell fluid in the tubing, there will be no variation in the tubingtension as the pump operates. Instead, there will be merely a periodicreduction of the load transmitted by the slips of the anchor to thecasing Whenever the pump piston is on the downstroke and the column ofwell fluid in the tubing is supported on the standing valve. The anchorof Figures 6-10 then has all the advantages of the anchor of Figures l5as to elimination of working of the tubing joints and consequentreduction of leakage as well as straightening of the tubing withconsequent reduction of wear between. tubing and sucker rods, prolongingthe life of both the sucker rods and tubing.

' Although the anchoring device described hereinabove has been indicatedto be useful as a tubing anchor in combination with a pumping wellassembly, it will find utility whenever it is desired to anchor a devicein a well or the like where the slip expander means operates to set theslips by an upward pull, for through the operation of the load transfermeans comprising the parting section and associated telescopic joint,the device can be transformed so that an upward pull tends to unset theslips. V

While preferred embodiments of the invention have been shown anddescribed, many modifications thereof can be 'made by one skilled in theart without departing from the spirit of the invention and it is desiredto protect by Letters Patent all forms of the invention falling withinthe scope of the following claims.

What I claim is:

1. A well pumping assembly comprising a well casing, a string of tubinginside said casing, means at the upper end of said casing for suspendingthe tubing from its upper end, a tubing anchor in said casing at a lowerpart of said tubing holding the tubing thereabove in tension throughoutits length after said tubing anchor is set, and a pump in said tubingabove said anchor; said anchor comprising a tubular body including atubular tapered slip expander means and a hollow mandrel connecting saidslip expander means to said tubing, a pluralityof slips around said slipexpander means, and slip control means connected to said tubular bodytending to hold said slips against axial movement relative to saidcasing while permitting radial movement of said slips between aretracted position and an extended position in anchoring engagement withthe casing; said hollow mandrel including a parting section, saidparting section comprising a length of said hollow mandrel having areduced wall thickness and integral with adjacent portions of saidmandrel, said reduced wall thickness of said parting section being lessthan the wall thickness of said tubing, and slip raising means on saidmandrel above said parting section adapted to engage with said slipcontrol means when said parting section has been parted to raise saidslips relative to said slip expander means, whereby upon application oftension to said string of tubing suflicient to rupture said partingsection an impact blow is produced on said slip raising means due tocontraction of said string of tubing.

2. A pipe anchor comprising a tubular slip expander means, tubular meansfor connecting said slip expander means to a string of pipe, saidtubular means including a parting section of tubular form havingcylindrical interior and exterior surfaces, said slip expander meansincluding an upwardly pointing expander cone, a plurality of slipsaround said cone, slip control means allowing radial movement of saidslips but preventing axial movement of said slips relative to said slipcontrol means, and means on said tubular means above said partingsection adapted to be engaged with said slip control means when saidparting section has been parted to raise said slips relative to saidcone, said parting section comprising a length of said tubular meansthat has a reduced wall thickness as compared to the remainder of saidtubular means, said parting section being integral with the portions ofsaid tubular means on both sides thereof, said parting section having areduced strength relative to axial tension as compared to the remainderof said tubular means.

3. A pipe anchor in accordance with claim 2 in which said slip expandermeans includes means on said cone engaging said slips to preventrelative motion therebetween except translation parallel to an elementof the cone, whereby upward movement of said slips relative to said conedraws said slips inwardly.

4. A pipe anchor according to claim 2 in which said slip control meansincludes a tubular slip cage having windows therein receiving saidslips, a tubular portion on the upper end of said slip cage surroundingand spaced from said tubular means providing an annulus therebetween,and a radial inturned annular flange at the upper end of said tubularportion, and said means on said tubular means adapted to be engaged withsaid slip con trol means includes a radial annular out-turned flange onsaid tubular means disposed within said annulus, and said slip controlmeans further includes a pin and slot connection between said slip cageand said slip expander means, said slot having a vertical portion and acircum- '8 ferential portion at the upper end thereof, said verticalportion having a length greater than the axial travel of said slipsrelative to said slip expander means and less than the axial length ofsaid annulus.

5. The combination of claim 2 in which said slip control means includesa tubular slip cage having windows therein receiving said slips, atubular portion on the upper end of said slip cage surrounding andspaced from said tubular means providing an annulus therebetween, and aradial inturned annular flange at the upper end of said tubular portion,and said means on said tubular means adapted to be engaged with saidslip control means includes a radial annular out-turned flange on saidtubular means disposed within said annulus, and the slip expander meanshas a threaded socket at its upper end receiving a threaded pin on thelower end of said tubular means, a second radial out-turned flange onsaid tubular means above said threaded pin and below the first saidradial out-turned flange forming a sealing shoulder engaging the upperend of said socket, and wherein said parting section is between saidradial out-turned flanges, the inner surface of said parting sectionbeing a finished surface.

References Cited in the file of this patent UNITED STATES PATENTS2,338,370 Wilson Jan. 4, 1944 2,350,973 Brumleu et a1. June 6, 19442,442,121 Earley May 25, 1948 2,564,240 Ware Aug. 14, 1951

